Re: [SQL] Re: [GENERAL] lztext and compression ratios...

Bruce Momjian <pgman@candle.pha.pa.us> writes:
>>     Compressor | level | heap size | toastrel | toastidx | seconds
>>                |       |           |   size   |   size   |
>>     -----------+-------+-----------+----------+----------+--------
>>     PGLZ       |   -   |   425,984 |  950,272 |   32,768 |    5.20
>>     zlib       |   1   |   499,712 |  614,400 |   16,384 |    6.85
>>     zlib       |   3   |   499,712 |  557,056 |   16,384 |    6.75
>>     zlib       |   6   |   491,520 |  524,288 |   16,384 |    7.10
>>     zlib       |   9   |   491,520 |  524,288 |   16,384 |    7.21
>
>Consider that the 25% slowness gets us a 35% disk reduction, and that
>translates to fewer buffer blocks and disk accesses.  Seems there is a
>clear tradeoff there.

Also, consider that in the vast majority of cases, reads greatly outnumber
writes for any given datum, and particularly so for web applications.

Could we get a benchmark that compared decompression speeds exclusively?
-Michael Robinson